/****************************************************************************
 *
 * ftimage.h
 *
 *   FreeType glyph image formats and default raster interface
 *   (specification).
 *
 * Copyright (C) 1996-2019 by
 * David Turner, Robert Wilhelm, and Werner Lemberg.
 *
 * This file is part of the FreeType project, and may only be used,
 * modified, and distributed under the terms of the FreeType project
 * license, LICENSE.TXT.  By continuing to use, modify, or distribute
 * this file you indicate that you have read the license and
 * understand and accept it fully.
 *
 */

/**************************************************************************
 *
 * Note: A 'raster' is simply a scan-line converter, used to render
 *       FT_Outlines into FT_Bitmaps.
 *
 */

#ifndef FTIMAGE_H_
#define FTIMAGE_H_

/* STANDALONE_ is from ftgrays.c */
#ifndef STANDALONE_
#include <ft2build.h>
#endif

FT_BEGIN_HEADER

/**************************************************************************
 *
 * @section:
 *   basic_types
 *
 */

/**************************************************************************
 *
 * @type:
 *   FT_Pos
 *
 * @description:
 *   The type FT_Pos is used to store vectorial coordinates.  Depending on
 *   the context, these can represent distances in integer font units, or
 *   16.16, or 26.6 fixed-point pixel coordinates.
 */
typedef signed long FT_Pos;

/**************************************************************************
 *
 * @struct:
 *   FT_Vector
 *
 * @description:
 *   A simple structure used to store a 2D vector; coordinates are of the
 *   FT_Pos type.
 *
 * @fields:
 *   x ::
 *     The horizontal coordinate.
 *   y ::
 *     The vertical coordinate.
 */
typedef struct FT_Vector_ {
	FT_Pos x;
	FT_Pos y;

} FT_Vector;

/**************************************************************************
 *
 * @struct:
 *   FT_BBox
 *
 * @description:
 *   A structure used to hold an outline's bounding box, i.e., the
 *   coordinates of its extrema in the horizontal and vertical directions.
 *
 * @fields:
 *   xMin ::
 *     The horizontal minimum (left-most).
 *
 *   yMin ::
 *     The vertical minimum (bottom-most).
 *
 *   xMax ::
 *     The horizontal maximum (right-most).
 *
 *   yMax ::
 *     The vertical maximum (top-most).
 *
 * @note:
 *   The bounding box is specified with the coordinates of the lower left
 *   and the upper right corner.  In PostScript, those values are often
 *   called (llx,lly) and (urx,ury), respectively.
 *
 *   If `yMin` is negative, this value gives the glyph's descender.
 *   Otherwise, the glyph doesn't descend below the baseline.  Similarly,
 *   if `ymax` is positive, this value gives the glyph's ascender.
 *
 *   `xMin` gives the horizontal distance from the glyph's origin to the
 *   left edge of the glyph's bounding box.  If `xMin` is negative, the
 *   glyph extends to the left of the origin.
 */
typedef struct FT_BBox_ {
	FT_Pos xMin, yMin;
	FT_Pos xMax, yMax;

} FT_BBox;

/**************************************************************************
 *
 * @enum:
 *   FT_Pixel_Mode
 *
 * @description:
 *   An enumeration type used to describe the format of pixels in a given
 *   bitmap.  Note that additional formats may be added in the future.
 *
 * @values:
 *   FT_PIXEL_MODE_NONE ::
 *     Value~0 is reserved.
 *
 *   FT_PIXEL_MODE_MONO ::
 *     A monochrome bitmap, using 1~bit per pixel.  Note that pixels are
 *     stored in most-significant order (MSB), which means that the
 *     left-most pixel in a byte has value 128.
 *
 *   FT_PIXEL_MODE_GRAY ::
 *     An 8-bit bitmap, generally used to represent anti-aliased glyph
 *     images.  Each pixel is stored in one byte.  Note that the number of
 *     'gray' levels is stored in the `num_grays` field of the @FT_Bitmap
 *     structure (it generally is 256).
 *
 *   FT_PIXEL_MODE_GRAY2 ::
 *     A 2-bit per pixel bitmap, used to represent embedded anti-aliased
 *     bitmaps in font files according to the OpenType specification.  We
 *     haven't found a single font using this format, however.
 *
 *   FT_PIXEL_MODE_GRAY4 ::
 *     A 4-bit per pixel bitmap, representing embedded anti-aliased bitmaps
 *     in font files according to the OpenType specification.  We haven't
 *     found a single font using this format, however.
 *
 *   FT_PIXEL_MODE_LCD ::
 *     An 8-bit bitmap, representing RGB or BGR decimated glyph images used
 *     for display on LCD displays; the bitmap is three times wider than
 *     the original glyph image.  See also @FT_RENDER_MODE_LCD.
 *
 *   FT_PIXEL_MODE_LCD_V ::
 *     An 8-bit bitmap, representing RGB or BGR decimated glyph images used
 *     for display on rotated LCD displays; the bitmap is three times
 *     taller than the original glyph image.  See also
 *     @FT_RENDER_MODE_LCD_V.
 *
 *   FT_PIXEL_MODE_BGRA ::
 *     [Since 2.5] An image with four 8-bit channels per pixel,
 *     representing a color image (such as emoticons) with alpha channel.
 *     For each pixel, the format is BGRA, which means, the blue channel
 *     comes first in memory.  The color channels are pre-multiplied and in
 *     the sRGB colorspace.  For example, full red at half-translucent
 *     opacity will be represented as '00,00,80,80', not '00,00,FF,80'.
 *     See also @FT_LOAD_COLOR.
 */
typedef enum FT_Pixel_Mode_ {
	FT_PIXEL_MODE_NONE = 0,
	FT_PIXEL_MODE_MONO,
	FT_PIXEL_MODE_GRAY,
	FT_PIXEL_MODE_GRAY2,
	FT_PIXEL_MODE_GRAY4,
	FT_PIXEL_MODE_LCD,
	FT_PIXEL_MODE_LCD_V,
	FT_PIXEL_MODE_BGRA,

	FT_PIXEL_MODE_MAX /* do not remove */

} FT_Pixel_Mode;

/* these constants are deprecated; use the corresponding `FT_Pixel_Mode` */
/* values instead.                                                       */
#define ft_pixel_mode_none FT_PIXEL_MODE_NONE
#define ft_pixel_mode_mono FT_PIXEL_MODE_MONO
#define ft_pixel_mode_grays FT_PIXEL_MODE_GRAY
#define ft_pixel_mode_pal2 FT_PIXEL_MODE_GRAY2
#define ft_pixel_mode_pal4 FT_PIXEL_MODE_GRAY4

/**************************************************************************
 *
 * @struct:
 *   FT_Bitmap
 *
 * @description:
 *   A structure used to describe a bitmap or pixmap to the raster.  Note
 *   that we now manage pixmaps of various depths through the `pixel_mode`
 *   field.
 *
 * @fields:
 *   rows ::
 *     The number of bitmap rows.
 *
 *   width ::
 *     The number of pixels in bitmap row.
 *
 *   pitch ::
 *     The pitch's absolute value is the number of bytes taken by one
 *     bitmap row, including padding.  However, the pitch is positive when
 *     the bitmap has a 'down' flow, and negative when it has an 'up' flow.
 *     In all cases, the pitch is an offset to add to a bitmap pointer in
 *     order to go down one row.
 *
 *     Note that 'padding' means the alignment of a bitmap to a byte
 *     border, and FreeType functions normally align to the smallest
 *     possible integer value.
 *
 *     For the B/W rasterizer, `pitch` is always an even number.
 *
 *     To change the pitch of a bitmap (say, to make it a multiple of 4),
 *     use @FT_Bitmap_Convert.  Alternatively, you might use callback
 *     functions to directly render to the application's surface; see the
 *     file `example2.cpp` in the tutorial for a demonstration.
 *
 *   buffer ::
 *     A typeless pointer to the bitmap buffer.  This value should be
 *     aligned on 32-bit boundaries in most cases.
 *
 *   num_grays ::
 *     This field is only used with @FT_PIXEL_MODE_GRAY; it gives the
 *     number of gray levels used in the bitmap.
 *
 *   pixel_mode ::
 *     The pixel mode, i.e., how pixel bits are stored.  See @FT_Pixel_Mode
 *     for possible values.
 *
 *   palette_mode ::
 *     This field is intended for paletted pixel modes; it indicates how
 *     the palette is stored.  Not used currently.
 *
 *   palette ::
 *     A typeless pointer to the bitmap palette; this field is intended for
 *     paletted pixel modes.  Not used currently.
 */
typedef struct FT_Bitmap_ {
	unsigned int rows;
	unsigned int width;
	int pitch;
	unsigned char *buffer;
	unsigned short num_grays;
	unsigned char pixel_mode;
	unsigned char palette_mode;
	void *palette;

} FT_Bitmap;

/**************************************************************************
 *
 * @section:
 *   outline_processing
 *
 */

/**************************************************************************
 *
 * @struct:
 *   FT_Outline
 *
 * @description:
 *   This structure is used to describe an outline to the scan-line
 *   converter.
 *
 * @fields:
 *   n_contours ::
 *     The number of contours in the outline.
 *
 *   n_points ::
 *     The number of points in the outline.
 *
 *   points ::
 *     A pointer to an array of `n_points` @FT_Vector elements, giving the
 *     outline's point coordinates.
 *
 *   tags ::
 *     A pointer to an array of `n_points` chars, giving each outline
 *     point's type.
 *
 *     If bit~0 is unset, the point is 'off' the curve, i.e., a Bezier
 *     control point, while it is 'on' if set.
 *
 *     Bit~1 is meaningful for 'off' points only.  If set, it indicates a
 *     third-order Bezier arc control point; and a second-order control
 *     point if unset.
 *
 *     If bit~2 is set, bits 5-7 contain the drop-out mode (as defined in
 *     the OpenType specification; the value is the same as the argument to
 *     the 'SCANMODE' instruction).
 *
 *     Bits 3 and~4 are reserved for internal purposes.
 *
 *   contours ::
 *     An array of `n_contours` shorts, giving the end point of each
 *     contour within the outline.  For example, the first contour is
 *     defined by the points '0' to `contours[0]`, the second one is
 *     defined by the points `contours[0]+1` to `contours[1]`, etc.
 *
 *   flags ::
 *     A set of bit flags used to characterize the outline and give hints
 *     to the scan-converter and hinter on how to convert/grid-fit it.  See
 *     @FT_OUTLINE_XXX.
 *
 * @note:
 *   The B/W rasterizer only checks bit~2 in the `tags` array for the first
 *   point of each contour.  The drop-out mode as given with
 *   @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, and
 *   @FT_OUTLINE_INCLUDE_STUBS in `flags` is then overridden.
 */
typedef struct FT_Outline_ {
	short n_contours; /* number of contours in glyph        */
	short n_points;   /* number of points in the glyph      */

	FT_Vector *points; /* the outline's points               */
	char *tags;        /* the points flags                   */
	short *contours;   /* the contour end points             */

	int flags; /* outline masks                      */

} FT_Outline;

/* */

/* Following limits must be consistent with */
/* FT_Outline.{n_contours,n_points}         */
#define FT_OUTLINE_CONTOURS_MAX SHRT_MAX
#define FT_OUTLINE_POINTS_MAX SHRT_MAX

/**************************************************************************
 *
 * @enum:
 *   FT_OUTLINE_XXX
 *
 * @description:
 *   A list of bit-field constants used for the flags in an outline's
 *   `flags` field.
 *
 * @values:
 *   FT_OUTLINE_NONE ::
 *     Value~0 is reserved.
 *
 *   FT_OUTLINE_OWNER ::
 *     If set, this flag indicates that the outline's field arrays (i.e.,
 *     `points`, `flags`, and `contours`) are 'owned' by the outline
 *     object, and should thus be freed when it is destroyed.
 *
 *   FT_OUTLINE_EVEN_ODD_FILL ::
 *     By default, outlines are filled using the non-zero winding rule.  If
 *     set to 1, the outline will be filled using the even-odd fill rule
 *     (only works with the smooth rasterizer).
 *
 *   FT_OUTLINE_REVERSE_FILL ::
 *     By default, outside contours of an outline are oriented in
 *     clock-wise direction, as defined in the TrueType specification.
 *     This flag is set if the outline uses the opposite direction
 *     (typically for Type~1 fonts).  This flag is ignored by the scan
 *     converter.
 *
 *   FT_OUTLINE_IGNORE_DROPOUTS ::
 *     By default, the scan converter will try to detect drop-outs in an
 *     outline and correct the glyph bitmap to ensure consistent shape
 *     continuity.  If set, this flag hints the scan-line converter to
 *     ignore such cases.  See below for more information.
 *
 *   FT_OUTLINE_SMART_DROPOUTS ::
 *     Select smart dropout control.  If unset, use simple dropout control.
 *     Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set.  See below for more
 *     information.
 *
 *   FT_OUTLINE_INCLUDE_STUBS ::
 *     If set, turn pixels on for 'stubs', otherwise exclude them.  Ignored
 *     if @FT_OUTLINE_IGNORE_DROPOUTS is set.  See below for more
 *     information.
 *
 *   FT_OUTLINE_HIGH_PRECISION ::
 *     This flag indicates that the scan-line converter should try to
 *     convert this outline to bitmaps with the highest possible quality.
 *     It is typically set for small character sizes.  Note that this is
 *     only a hint that might be completely ignored by a given
 *     scan-converter.
 *
 *   FT_OUTLINE_SINGLE_PASS ::
 *     This flag is set to force a given scan-converter to only use a
 *     single pass over the outline to render a bitmap glyph image.
 *     Normally, it is set for very large character sizes.  It is only a
 *     hint that might be completely ignored by a given scan-converter.
 *
 * @note:
 *   The flags @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, and
 *   @FT_OUTLINE_INCLUDE_STUBS are ignored by the smooth rasterizer.
 *
 *   There exists a second mechanism to pass the drop-out mode to the B/W
 *   rasterizer; see the `tags` field in @FT_Outline.
 *
 *   Please refer to the description of the 'SCANTYPE' instruction in the
 *   OpenType specification (in file `ttinst1.doc`) how simple drop-outs,
 *   smart drop-outs, and stubs are defined.
 */
#define FT_OUTLINE_NONE 0x0
#define FT_OUTLINE_OWNER 0x1
#define FT_OUTLINE_EVEN_ODD_FILL 0x2
#define FT_OUTLINE_REVERSE_FILL 0x4
#define FT_OUTLINE_IGNORE_DROPOUTS 0x8
#define FT_OUTLINE_SMART_DROPOUTS 0x10
#define FT_OUTLINE_INCLUDE_STUBS 0x20

#define FT_OUTLINE_HIGH_PRECISION 0x100
#define FT_OUTLINE_SINGLE_PASS 0x200

/* these constants are deprecated; use the corresponding */
/* `FT_OUTLINE_XXX` values instead                       */
#define ft_outline_none FT_OUTLINE_NONE
#define ft_outline_owner FT_OUTLINE_OWNER
#define ft_outline_even_odd_fill FT_OUTLINE_EVEN_ODD_FILL
#define ft_outline_reverse_fill FT_OUTLINE_REVERSE_FILL
#define ft_outline_ignore_dropouts FT_OUTLINE_IGNORE_DROPOUTS
#define ft_outline_high_precision FT_OUTLINE_HIGH_PRECISION
#define ft_outline_single_pass FT_OUTLINE_SINGLE_PASS

/* */

#define FT_CURVE_TAG(flag) (flag & 0x03)

/* see the `tags` field in `FT_Outline` for a description of the values */
#define FT_CURVE_TAG_ON 0x01
#define FT_CURVE_TAG_CONIC 0x00
#define FT_CURVE_TAG_CUBIC 0x02

#define FT_CURVE_TAG_HAS_SCANMODE 0x04

#define FT_CURVE_TAG_TOUCH_X 0x08 /* reserved for TrueType hinter */
#define FT_CURVE_TAG_TOUCH_Y 0x10 /* reserved for TrueType hinter */

#define FT_CURVE_TAG_TOUCH_BOTH (FT_CURVE_TAG_TOUCH_X | FT_CURVE_TAG_TOUCH_Y)
/* values 0x20, 0x40, and 0x80 are reserved */

/* these constants are deprecated; use the corresponding */
/* `FT_CURVE_TAG_XXX` values instead                     */
#define FT_Curve_Tag_On FT_CURVE_TAG_ON
#define FT_Curve_Tag_Conic FT_CURVE_TAG_CONIC
#define FT_Curve_Tag_Cubic FT_CURVE_TAG_CUBIC
#define FT_Curve_Tag_Touch_X FT_CURVE_TAG_TOUCH_X
#define FT_Curve_Tag_Touch_Y FT_CURVE_TAG_TOUCH_Y

/**************************************************************************
 *
 * @functype:
 *   FT_Outline_MoveToFunc
 *
 * @description:
 *   A function pointer type used to describe the signature of a 'move to'
 *   function during outline walking/decomposition.
 *
 *   A 'move to' is emitted to start a new contour in an outline.
 *
 * @input:
 *   to ::
 *     A pointer to the target point of the 'move to'.
 *
 *   user ::
 *     A typeless pointer, which is passed from the caller of the
 *     decomposition function.
 *
 * @return:
 *   Error code.  0~means success.
 */
typedef int (*FT_Outline_MoveToFunc)(const FT_Vector *to, void *user);

#define FT_Outline_MoveTo_Func FT_Outline_MoveToFunc

/**************************************************************************
 *
 * @functype:
 *   FT_Outline_LineToFunc
 *
 * @description:
 *   A function pointer type used to describe the signature of a 'line to'
 *   function during outline walking/decomposition.
 *
 *   A 'line to' is emitted to indicate a segment in the outline.
 *
 * @input:
 *   to ::
 *     A pointer to the target point of the 'line to'.
 *
 *   user ::
 *     A typeless pointer, which is passed from the caller of the
 *     decomposition function.
 *
 * @return:
 *   Error code.  0~means success.
 */
typedef int (*FT_Outline_LineToFunc)(const FT_Vector *to, void *user);

#define FT_Outline_LineTo_Func FT_Outline_LineToFunc

/**************************************************************************
 *
 * @functype:
 *   FT_Outline_ConicToFunc
 *
 * @description:
 *   A function pointer type used to describe the signature of a 'conic to'
 *   function during outline walking or decomposition.
 *
 *   A 'conic to' is emitted to indicate a second-order Bezier arc in the
 *   outline.
 *
 * @input:
 *   control ::
 *     An intermediate control point between the last position and the new
 *     target in `to`.
 *
 *   to ::
 *     A pointer to the target end point of the conic arc.
 *
 *   user ::
 *     A typeless pointer, which is passed from the caller of the
 *     decomposition function.
 *
 * @return:
 *   Error code.  0~means success.
 */
typedef int (*FT_Outline_ConicToFunc)(const FT_Vector *control, const FT_Vector *to, void *user);

#define FT_Outline_ConicTo_Func FT_Outline_ConicToFunc

/**************************************************************************
 *
 * @functype:
 *   FT_Outline_CubicToFunc
 *
 * @description:
 *   A function pointer type used to describe the signature of a 'cubic to'
 *   function during outline walking or decomposition.
 *
 *   A 'cubic to' is emitted to indicate a third-order Bezier arc.
 *
 * @input:
 *   control1 ::
 *     A pointer to the first Bezier control point.
 *
 *   control2 ::
 *     A pointer to the second Bezier control point.
 *
 *   to ::
 *     A pointer to the target end point.
 *
 *   user ::
 *     A typeless pointer, which is passed from the caller of the
 *     decomposition function.
 *
 * @return:
 *   Error code.  0~means success.
 */
typedef int (*FT_Outline_CubicToFunc)(const FT_Vector *control1, const FT_Vector *control2,
                                      const FT_Vector *to, void *user);

#define FT_Outline_CubicTo_Func FT_Outline_CubicToFunc

/**************************************************************************
 *
 * @struct:
 *   FT_Outline_Funcs
 *
 * @description:
 *   A structure to hold various function pointers used during outline
 *   decomposition in order to emit segments, conic, and cubic Beziers.
 *
 * @fields:
 *   move_to ::
 *     The 'move to' emitter.
 *
 *   line_to ::
 *     The segment emitter.
 *
 *   conic_to ::
 *     The second-order Bezier arc emitter.
 *
 *   cubic_to ::
 *     The third-order Bezier arc emitter.
 *
 *   shift ::
 *     The shift that is applied to coordinates before they are sent to the
 *     emitter.
 *
 *   delta ::
 *     The delta that is applied to coordinates before they are sent to the
 *     emitter, but after the shift.
 *
 * @note:
 *   The point coordinates sent to the emitters are the transformed version
 *   of the original coordinates (this is important for high accuracy
 *   during scan-conversion).  The transformation is simple:
 *
 *   ```
 *     x' = (x << shift) - delta
 *     y' = (y << shift) - delta
 *   ```
 *
 *   Set the values of `shift` and `delta` to~0 to get the original point
 *   coordinates.
 */
typedef struct FT_Outline_Funcs_ {
	FT_Outline_MoveToFunc move_to;
	FT_Outline_LineToFunc line_to;
	FT_Outline_ConicToFunc conic_to;
	FT_Outline_CubicToFunc cubic_to;

	int shift;
	FT_Pos delta;

} FT_Outline_Funcs;

/**************************************************************************
 *
 * @section:
 *   basic_types
 *
 */

/**************************************************************************
 *
 * @macro:
 *   FT_IMAGE_TAG
 *
 * @description:
 *   This macro converts four-letter tags to an unsigned long type.
 *
 * @note:
 *   Since many 16-bit compilers don't like 32-bit enumerations, you should
 *   redefine this macro in case of problems to something like this:
 *
 *   ```
 *     #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 )  value
 *   ```
 *
 *   to get a simple enumeration without assigning special numbers.
 */
#ifndef FT_IMAGE_TAG
#define FT_IMAGE_TAG(value, _x1, _x2, _x3, _x4)                                                    \
	value = (((unsigned long)_x1 << 24) | ((unsigned long)_x2 << 16) | ((unsigned long)_x3 << 8) | \
	         (unsigned long)_x4)
#endif /* FT_IMAGE_TAG */

/**************************************************************************
 *
 * @enum:
 *   FT_Glyph_Format
 *
 * @description:
 *   An enumeration type used to describe the format of a given glyph
 *   image.  Note that this version of FreeType only supports two image
 *   formats, even though future font drivers will be able to register
 *   their own format.
 *
 * @values:
 *   FT_GLYPH_FORMAT_NONE ::
 *     The value~0 is reserved.
 *
 *   FT_GLYPH_FORMAT_COMPOSITE ::
 *     The glyph image is a composite of several other images.  This format
 *     is _only_ used with @FT_LOAD_NO_RECURSE, and is used to report
 *     compound glyphs (like accented characters).
 *
 *   FT_GLYPH_FORMAT_BITMAP ::
 *     The glyph image is a bitmap, and can be described as an @FT_Bitmap.
 *     You generally need to access the `bitmap` field of the
 *     @FT_GlyphSlotRec structure to read it.
 *
 *   FT_GLYPH_FORMAT_OUTLINE ::
 *     The glyph image is a vectorial outline made of line segments and
 *     Bezier arcs; it can be described as an @FT_Outline; you generally
 *     want to access the `outline` field of the @FT_GlyphSlotRec structure
 *     to read it.
 *
 *   FT_GLYPH_FORMAT_PLOTTER ::
 *     The glyph image is a vectorial path with no inside and outside
 *     contours.  Some Type~1 fonts, like those in the Hershey family,
 *     contain glyphs in this format.  These are described as @FT_Outline,
 *     but FreeType isn't currently capable of rendering them correctly.
 */
typedef enum FT_Glyph_Format_ {
	FT_IMAGE_TAG(FT_GLYPH_FORMAT_NONE, 0, 0, 0, 0),

	FT_IMAGE_TAG(FT_GLYPH_FORMAT_COMPOSITE, 'c', 'o', 'm', 'p'),
	FT_IMAGE_TAG(FT_GLYPH_FORMAT_BITMAP, 'b', 'i', 't', 's'),
	FT_IMAGE_TAG(FT_GLYPH_FORMAT_OUTLINE, 'o', 'u', 't', 'l'),
	FT_IMAGE_TAG(FT_GLYPH_FORMAT_PLOTTER, 'p', 'l', 'o', 't')

} FT_Glyph_Format;

/* these constants are deprecated; use the corresponding */
/* `FT_Glyph_Format` values instead.                     */
#define ft_glyph_format_none FT_GLYPH_FORMAT_NONE
#define ft_glyph_format_composite FT_GLYPH_FORMAT_COMPOSITE
#define ft_glyph_format_bitmap FT_GLYPH_FORMAT_BITMAP
#define ft_glyph_format_outline FT_GLYPH_FORMAT_OUTLINE
#define ft_glyph_format_plotter FT_GLYPH_FORMAT_PLOTTER

/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****            R A S T E R   D E F I N I T I O N S                *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/

/**************************************************************************
 *
 * A raster is a scan converter, in charge of rendering an outline into a
 * bitmap.  This section contains the public API for rasters.
 *
 * Note that in FreeType 2, all rasters are now encapsulated within
 * specific modules called 'renderers'.  See `ftrender.h` for more details
 * on renderers.
 *
 */

/**************************************************************************
 *
 * @section:
 *   raster
 *
 * @title:
 *   Scanline Converter
 *
 * @abstract:
 *   How vectorial outlines are converted into bitmaps and pixmaps.
 *
 * @description:
 *   This section contains technical definitions.
 *
 * @order:
 *   FT_Raster
 *   FT_Span
 *   FT_SpanFunc
 *
 *   FT_Raster_Params
 *   FT_RASTER_FLAG_XXX
 *
 *   FT_Raster_NewFunc
 *   FT_Raster_DoneFunc
 *   FT_Raster_ResetFunc
 *   FT_Raster_SetModeFunc
 *   FT_Raster_RenderFunc
 *   FT_Raster_Funcs
 *
 */

/**************************************************************************
 *
 * @type:
 *   FT_Raster
 *
 * @description:
 *   An opaque handle (pointer) to a raster object.  Each object can be
 *   used independently to convert an outline into a bitmap or pixmap.
 */
typedef struct FT_RasterRec_ *FT_Raster;

/**************************************************************************
 *
 * @struct:
 *   FT_Span
 *
 * @description:
 *   A structure used to model a single span of gray pixels when rendering
 *   an anti-aliased bitmap.
 *
 * @fields:
 *   x ::
 *     The span's horizontal start position.
 *
 *   len ::
 *     The span's length in pixels.
 *
 *   coverage ::
 *     The span color/coverage, ranging from 0 (background) to 255
 *     (foreground).
 *
 * @note:
 *   This structure is used by the span drawing callback type named
 *   @FT_SpanFunc that takes the y~coordinate of the span as a parameter.
 *
 *   The coverage value is always between 0 and 255.  If you want less gray
 *   values, the callback function has to reduce them.
 */
typedef struct FT_Span_ {
	short x;
	unsigned short len;
	unsigned char coverage;

} FT_Span;

/**************************************************************************
 *
 * @functype:
 *   FT_SpanFunc
 *
 * @description:
 *   A function used as a call-back by the anti-aliased renderer in order
 *   to let client applications draw themselves the gray pixel spans on
 *   each scan line.
 *
 * @input:
 *   y ::
 *     The scanline's upward y~coordinate.
 *
 *   count ::
 *     The number of spans to draw on this scanline.
 *
 *   spans ::
 *     A table of `count` spans to draw on the scanline.
 *
 *   user ::
 *     User-supplied data that is passed to the callback.
 *
 * @note:
 *   This callback allows client applications to directly render the gray
 *   spans of the anti-aliased bitmap to any kind of surfaces.
 *
 *   This can be used to write anti-aliased outlines directly to a given
 *   background bitmap, and even perform translucency.
 */
typedef void (*FT_SpanFunc)(int y, int count, const FT_Span *spans, void *user);

#define FT_Raster_Span_Func FT_SpanFunc

/**************************************************************************
 *
 * @functype:
 *   FT_Raster_BitTest_Func
 *
 * @description:
 *   Deprecated, unimplemented.
 */
typedef int (*FT_Raster_BitTest_Func)(int y, int x, void *user);

/**************************************************************************
 *
 * @functype:
 *   FT_Raster_BitSet_Func
 *
 * @description:
 *   Deprecated, unimplemented.
 */
typedef void (*FT_Raster_BitSet_Func)(int y, int x, void *user);

/**************************************************************************
 *
 * @enum:
 *   FT_RASTER_FLAG_XXX
 *
 * @description:
 *   A list of bit flag constants as used in the `flags` field of a
 *   @FT_Raster_Params structure.
 *
 * @values:
 *   FT_RASTER_FLAG_DEFAULT ::
 *     This value is 0.
 *
 *   FT_RASTER_FLAG_AA ::
 *     This flag is set to indicate that an anti-aliased glyph image should
 *     be generated.  Otherwise, it will be monochrome (1-bit).
 *
 *   FT_RASTER_FLAG_DIRECT ::
 *     This flag is set to indicate direct rendering.  In this mode, client
 *     applications must provide their own span callback.  This lets them
 *     directly draw or compose over an existing bitmap.  If this bit is
 *     _not_ set, the target pixmap's buffer _must_ be zeroed before
 *     rendering and the output will be clipped to its size.
 *
 *     Direct rendering is only possible with anti-aliased glyphs.
 *
 *   FT_RASTER_FLAG_CLIP ::
 *     This flag is only used in direct rendering mode.  If set, the output
 *     will be clipped to a box specified in the `clip_box` field of the
 *     @FT_Raster_Params structure.  Otherwise, the `clip_box` is
 *     effectively set to the bounding box and all spans are generated.
 */
#define FT_RASTER_FLAG_DEFAULT 0x0
#define FT_RASTER_FLAG_AA 0x1
#define FT_RASTER_FLAG_DIRECT 0x2
#define FT_RASTER_FLAG_CLIP 0x4

/* these constants are deprecated; use the corresponding */
/* `FT_RASTER_FLAG_XXX` values instead                   */
#define ft_raster_flag_default FT_RASTER_FLAG_DEFAULT
#define ft_raster_flag_aa FT_RASTER_FLAG_AA
#define ft_raster_flag_direct FT_RASTER_FLAG_DIRECT
#define ft_raster_flag_clip FT_RASTER_FLAG_CLIP

/**************************************************************************
 *
 * @struct:
 *   FT_Raster_Params
 *
 * @description:
 *   A structure to hold the parameters used by a raster's render function,
 *   passed as an argument to @FT_Outline_Render.
 *
 * @fields:
 *   target ::
 *     The target bitmap.
 *
 *   source ::
 *     A pointer to the source glyph image (e.g., an @FT_Outline).
 *
 *   flags ::
 *     The rendering flags.
 *
 *   gray_spans ::
 *     The gray span drawing callback.
 *
 *   black_spans ::
 *     Unused.
 *
 *   bit_test ::
 *     Unused.
 *
 *   bit_set ::
 *     Unused.
 *
 *   user ::
 *     User-supplied data that is passed to each drawing callback.
 *
 *   clip_box ::
 *     An optional clipping box.  It is only used in direct rendering mode.
 *     Note that coordinates here should be expressed in _integer_ pixels
 *     (and not in 26.6 fixed-point units).
 *
 * @note:
 *   An anti-aliased glyph bitmap is drawn if the @FT_RASTER_FLAG_AA bit
 *   flag is set in the `flags` field, otherwise a monochrome bitmap is
 *   generated.
 *
 *   If the @FT_RASTER_FLAG_DIRECT bit flag is set in `flags`, the raster
 *   will call the `gray_spans` callback to draw gray pixel spans.  This
 *   allows direct composition over a pre-existing bitmap through
 *   user-provided callbacks to perform the span drawing and composition.
 *   Not supported by the monochrome rasterizer.
 */
typedef struct FT_Raster_Params_ {
	const FT_Bitmap *target;
	const void *source;
	int flags;
	FT_SpanFunc gray_spans;
	FT_SpanFunc black_spans;         /* unused */
	FT_Raster_BitTest_Func bit_test; /* unused */
	FT_Raster_BitSet_Func bit_set;   /* unused */
	void *user;
	FT_BBox clip_box;

} FT_Raster_Params;

/**************************************************************************
 *
 * @functype:
 *   FT_Raster_NewFunc
 *
 * @description:
 *   A function used to create a new raster object.
 *
 * @input:
 *   memory ::
 *     A handle to the memory allocator.
 *
 * @output:
 *   raster ::
 *     A handle to the new raster object.
 *
 * @return:
 *   Error code.  0~means success.
 *
 * @note:
 *   The `memory` parameter is a typeless pointer in order to avoid
 *   un-wanted dependencies on the rest of the FreeType code.  In practice,
 *   it is an @FT_Memory object, i.e., a handle to the standard FreeType
 *   memory allocator.  However, this field can be completely ignored by a
 *   given raster implementation.
 */
typedef int (*FT_Raster_NewFunc)(void *memory, FT_Raster *raster);

#define FT_Raster_New_Func FT_Raster_NewFunc

/**************************************************************************
 *
 * @functype:
 *   FT_Raster_DoneFunc
 *
 * @description:
 *   A function used to destroy a given raster object.
 *
 * @input:
 *   raster ::
 *     A handle to the raster object.
 */
typedef void (*FT_Raster_DoneFunc)(FT_Raster raster);

#define FT_Raster_Done_Func FT_Raster_DoneFunc

/**************************************************************************
 *
 * @functype:
 *   FT_Raster_ResetFunc
 *
 * @description:
 *   FreeType used to provide an area of memory called the 'render pool'
 *   available to all registered rasterizers.  This was not thread safe,
 *   however, and now FreeType never allocates this pool.
 *
 *   This function is called after a new raster object is created.
 *
 * @input:
 *   raster ::
 *     A handle to the new raster object.
 *
 *   pool_base ::
 *     Previously, the address in memory of the render pool.  Set this to
 *     `NULL`.
 *
 *   pool_size ::
 *     Previously, the size in bytes of the render pool.  Set this to 0.
 *
 * @note:
 *   Rasterizers should rely on dynamic or stack allocation if they want to
 *   (a handle to the memory allocator is passed to the rasterizer
 *   constructor).
 */
typedef void (*FT_Raster_ResetFunc)(FT_Raster raster, unsigned char *pool_base,
                                    unsigned long pool_size);

#define FT_Raster_Reset_Func FT_Raster_ResetFunc

/**************************************************************************
 *
 * @functype:
 *   FT_Raster_SetModeFunc
 *
 * @description:
 *   This function is a generic facility to change modes or attributes in a
 *   given raster.  This can be used for debugging purposes, or simply to
 *   allow implementation-specific 'features' in a given raster module.
 *
 * @input:
 *   raster ::
 *     A handle to the new raster object.
 *
 *   mode ::
 *     A 4-byte tag used to name the mode or property.
 *
 *   args ::
 *     A pointer to the new mode/property to use.
 */
typedef int (*FT_Raster_SetModeFunc)(FT_Raster raster, unsigned long mode, void *args);

#define FT_Raster_Set_Mode_Func FT_Raster_SetModeFunc

/**************************************************************************
 *
 * @functype:
 *   FT_Raster_RenderFunc
 *
 * @description:
 *   Invoke a given raster to scan-convert a given glyph image into a
 *   target bitmap.
 *
 * @input:
 *   raster ::
 *     A handle to the raster object.
 *
 *   params ::
 *     A pointer to an @FT_Raster_Params structure used to store the
 *     rendering parameters.
 *
 * @return:
 *   Error code.  0~means success.
 *
 * @note:
 *   The exact format of the source image depends on the raster's glyph
 *   format defined in its @FT_Raster_Funcs structure.  It can be an
 *   @FT_Outline or anything else in order to support a large array of
 *   glyph formats.
 *
 *   Note also that the render function can fail and return a
 *   `FT_Err_Unimplemented_Feature` error code if the raster used does not
 *   support direct composition.
 */
typedef int (*FT_Raster_RenderFunc)(FT_Raster raster, const FT_Raster_Params *params);

#define FT_Raster_Render_Func FT_Raster_RenderFunc

/**************************************************************************
 *
 * @struct:
 *   FT_Raster_Funcs
 *
 * @description:
 *  A structure used to describe a given raster class to the library.
 *
 * @fields:
 *   glyph_format ::
 *     The supported glyph format for this raster.
 *
 *   raster_new ::
 *     The raster constructor.
 *
 *   raster_reset ::
 *     Used to reset the render pool within the raster.
 *
 *   raster_render ::
 *     A function to render a glyph into a given bitmap.
 *
 *   raster_done ::
 *     The raster destructor.
 */
typedef struct FT_Raster_Funcs_ {
	FT_Glyph_Format glyph_format;

	FT_Raster_NewFunc raster_new;
	FT_Raster_ResetFunc raster_reset;
	FT_Raster_SetModeFunc raster_set_mode;
	FT_Raster_RenderFunc raster_render;
	FT_Raster_DoneFunc raster_done;

} FT_Raster_Funcs;

/* */

FT_END_HEADER

#endif /* FTIMAGE_H_ */

/* END */

/* Local Variables: */
/* coding: utf-8    */
/* End:             */
